advisers to politicals wrote a letter warning of dire consequences if the u.s. does not get its deficits under control. one of the writers ed lazear who served under president bush from 2006 to 2009. he is currently a professor at stanford university at the hoover institute, and he joins us with more. great to you on the program. >> good to see you again. thank you. >> let me start with that letter. you and those other economists come from all parts of the political spectrum, yet you bring on this. why is it so important? >> well, it's important because the debt will have very significant impact on economic growth. the big problem that we're worried about is right now we stand at a debt to gdp ratio at about 62%. by the end of this year, if the president's budget goes into effect, we'll be talking about 72%. and what the economists warn us, people who have studied this is when we get close to 90%, we have very significant negative effects on our growth. the big problem, of course, is that once we start getting very high debt ratios, we have to service that debt, which means that we have